Turbine ring assembly

Abstract

A turbine ring assembly including ring sectors forming a turbine ring and a ring support structure, each ring sector having, along a section plane defined by an axial direction and a radial direction of the ring, a portion forming an annular base with, in the radial direction an inner face defining the inner face of the ring and an outer face from which a first and a second attachment tabs protrude, the structure including a central shroud from which a first and a second radial clamps protrude between which the first and second attachment tabs of each ring sector are maintained. It includes a first and a second annular flanges removably fastened to the first radial clamp of the central shroud and separated from each other by a contact abutment.

The invention claimed is: 
     
       1. A turbine ring assembly comprising:
 a plurality of ring sectors forming a turbine ring, each ring sector being made of ceramic-matrix composite material and having, along a section plane defined by an axial direction and a radial direction of the turbine ring, a portion forming an annular base with, in the radial direction of the turbine ring, an inner face defining the inner face of the turbine ring and an outer face from which a first attachment tab and a second attachment tab protrude; 
 a ring support structure, the ring support structure being made of metal and including a central shroud from which a first radial clamp and a second radial clamp protrude between which the first attachment tab and the second attachment tab of each ring sector are maintained; 
 a first annular flange; and 
 a second annular flange disposed upstream of the first annular flange with respect to a direction of an air flow intended to pass through the turbine ring assembly, 
 wherein the first and second annular flanges each respectively have a first free radial end and a second radial end opposite to the first free radial end, the first free radial end of the first flange bearing axially against the first attachment tab, the first free radial end of the second annular flange being distant from the first free radial end of the first annular flange in the axial direction, 
 wherein the second radial ends of the first annular flange and second annular flange are removably fastened to the first radial clamp of the central shroud of the ring support structure such that the second radial end of the first annular flange is sandwiched between the first radial clamp of the central shroud of the ring support structure and the second radial end of the second annular flange, 
 wherein the first annular flange and the second annular flange are shrink-fitted to the ring support structure, the second radial end of the second annular flange abutting an inner surface of the central shroud of the ring support structure in the radial direction, and a portion of the first annular flange abutting the ring support structure in the radial direction, and 
 wherein one of the second radial end of the first annular flange and the second radial end of the second annular flange presents a contact abutment protruding in the axial direction and abutting axially the other of the second radial end of the first annular flange and the second radial end of the second annular flange. 
 
     
     
       2. The assembly according to  claim 1 , wherein the first annular flange comprises the contact abutment. 
     
     
       3. The assembly according to  claim 1 , wherein the second annular flange comprises the contact abutment. 
     
     
       4. The assembly according to  claim 1 , wherein the first flange has a thickness in the axial direction smaller than the thickness in the axial direction of the second flange. 
     
     
       5. The assembly according to  claim 4 , wherein the central shroud of the ring support structure has a variable radius in the axial direction, the radius of the central shroud decreasing along the direction of the air flow intended to pass through the turbine ring assembly. 
     
     
       6. The assembly according to  claim 4 , wherein the second radial clamp of the ring support structure has a first free radial end and a second radial end secured to the central shroud of the ring support structure, the first free radial end of the second radial clamp being in contact with the second attachment tab of the turbine ring and having a thickness in the axial direction greater than the thickness of the first end of the first annular flange. 
     
     
       7. The assembly according to  claim 1 , wherein the ring sector has W inverted π-shaped section along the section plane defined by the axial direction and the radial direction, wherein the assembly comprises, for each ring sector, at least three pins to radially hold the ring sector in position, and wherein the first attachment tab and the second attachment tab of each ring sector each comprises a first radial end secured to the outer face of the annular base, a second free radial end, and at least three lugs for receiving said at least three pins, at least two lugs of said at least three lugs protruding from the second radial end of one of the first attachment tab or the second attachment tab in the radial direction of the turbine ring and at least one lug of said at least three lugs protruding from the second radial end of the other of the first attachment tab and the second attachment tab in the radial direction of the turbine ring, each of said at least three lugs including an orifice for receiving one of the pins. 
     
     
       8. The assembly according to  claim 1 , wherein the ring sector has a K-section along the section plane defined by the axial direction and the radial direction, the first attachment tab and the second attachment tab having an S-shape. 
     
     
       9. The assembly according to  claim 1 , wherein the ring sector has an O-shaped section along the section plane defined by the axial direction and the radial direction, the first attachment tab and the second attachment tab each having a first end secured to the outer face and a second free end, and
 wherein each ring sector comprises a third attachment tab and a fourth attachment tab each extending, in the axial direction of the turbine ring, between a second radial end of the first attachment tab and a second radial end of the second attachment tab, each ring sector being fastened to the ring support structure by a fastening screw including a screw head bearing against the ring support structure and a thread cooperating with a tapping formed in a fastening plate, the fastening plate cooperating with the third attachment tab and the fourth attachment tab. 
 
     
     
       10. A turbomachine comprising a turbine ring assembly according to  claim 1 .